"General This European Telecommunication Standard (ETS) defines the stage 1 for the Universal Access Number (UAN) service. Stage 1 is an overall service description@ primarily from the service subscriber's and user's point of view@ but does not deal with the details of the human interface itself. This ETS includes information applicable to network operators@ service providers and terminal@ switch and database manufactures. NOTE: In some fora@ this service is also referred to as the ""shared cost service"". This ETS specifies the requirements where the service is provided to the user via a telecommunications network that is either the pan-European Integrated Services Digital Network (ISDN) or any other Public Switched Telephone Network (PSTN) as provided by European public telecommunications operators. The requirements different from those of the basic call where the UAN service is provided to the user via a mobile network are outside the scope of this ETS. However@ if calls to the UAN service originate or terminate in a mobile network and any special procedure above those for the basic call has to be performed@ this is be stated in the subclause 7.1 dealing with the interworking between ISDNs@ PSTNs and mobile networks. This ETS contains the core requirements for the UAN service which are sufficient to provide a complete service. This ETS also documents some additional requirements which can be implemented (but do not have to be implemented). Furthermore@ additional functionalities not documented in this ETS may be implemented. The requirements of which are considered outside the scope of this ETS and consequently outside the scope of the corresponding stage 2 and stage 3 standards. This additional functionality may be on a network-wide basis@ or particular to one or a group of users. Such additional functionality shall not compromise conformance to the core requirements of the service. Charging principles are outside the scope of this ETS@ unless specific service requirements are stated. These requirements deal with the allocation of certain call charges to particular users. Interactions with services/supplementary services not listed in clauses 8 and 9 are outside the scope of this ETS. Interactions between optional UAN service features and ISDN supplementary services are outside the scope of this ETS@ unless a specific indication is given. Definition and applicability The UAN service allows the service subscriber having one or several installations to be reached from all or part of the network with a unique universal access number. Calls to the universal access number shall be routed to destinations defined by the service subscriber. The UAN service is applicable to all telecommunication services using numbers conforming to the numbering plan and structure specified in CCITT Recommendation E.164 [2]. This ETS is applicable to the stage 2 and stage 3 standards for the UAN service@ where the text indicates the status of a requirement (i.e. as strict command or prohibition@ as authorization leaving freedom@ as a capability or a possibility)@ this shall be reflected in the relevant stage 2 and stage 3 standards. Otherwise the status of a requirement shall be reflected in the relevant standards for the underlying protocols. Furthermore@ conformance to this ETS is either met by: - conforming to the stage 3 standards; or - implicitly covered by conforming to the standards for the underlying protocols; with the field of application appropriate to the equipment being implemented. Therefore no method of testing is provided for this ETS."